Apparatus for molding hollow bodies



P. A. E. ARMSTRONG.

APPARATUS FOR MOLDING HOLLOW BODIES,-

APPLICATION FILED JAN- 22, I921.

Lfi A Patented May 23, 1922;, 72W 725' PEURGY A. E. ARMSTRONG, 01FLOUDONVILLE, NEW YORK.

APPARATUS FOR MOLDING HQ-LLOW BODIES.

iaiaeev.

Application filed January 22, 1921.

, have invented'certain new and useful Tmprovements in Apparatus forMolding Hollow Bodies, of which the following is a' specification.

My invention relates to apparatus for making cast hollow bodies, such aspipes, columns, hollow ingots and the like. The present invention isconcerned with the cores used in making hollow castings. v

In proceeding'in accordancewith my invention, the core is preferablyarranged upon a rod or tube preferably of metal, and the core ispreferably made up in a plurality of rings or sections, having openingstherein for the passage of the rod or tube whereby the core portions arepositioned, preferably centered, directly on the tube or rod. The coresections are preferably all of like form, so that a single pattern willserve for mak ing all the core sections, and the core sections are soconstructed that while they are supported with ample strength andfirmness and give ample support to the metal of the casting while moltenand in the preliminary stages of solidification, they give way as soonas any substantial shrinking or other stresses are imposed, permittingthe whole casting to solidify naturally without hindrance and in themanner best suited to its particular composition and free from anytendency to formation of cracks or the like.

Tmsecure this and related results the'core sections are preferably madeof molding sand'provided with interior portions of re duced density, asfor example they may con- .tain air spaces or spaces filled or partiallyfilled with light porous materials, so that they canreadily give way aswhen shrinking of the hollow'c'asting takes place, leaving the same toshrink freely and naturally as if the core had been removed, the extraspaces provided within the core sections being suflicient to provideample room for all the broken down material of the core sections as thecasting shrinks. This broken'down material can be readily removed whenthe hollow casting has Specification of Letters Patent.

of Great Patented May 23, Serial No. 439,184.

or 1n equivalent ways.

W1th the foregoing and related objects in v ew, my invention consists inthe combinations and apparatus herein described and claimed.

In the drawings showing preferred forms of apparatus, Fig. 1 is alongitudinal-sect1ona1 View of a mold and core having a perforatedtubular core center, and Figs. 2-5 are fragmentary views similar to Fig.1 but showing modified forms of core sect1ons arranged upon a rodinstead of a tube.

Reference character 10 designates a tubu-- lar core center having gasvent holes 11. The mold core sections 12, 12 may be of var ousmaterials, but are preferably oil-sand cores made from the same patternand baked. In the form shown in Fig. 1 core sections 12 are preferablycylindrical but maybe of varlous cross-sectional forms as desired, andmay be conveniently described as being substantlally of inverted cupform, having side walls 13 and a base or head 14. The portion 14 isprovided with an opening 15, adapted to fit on the central tube 10 andto center the mold sections thereon.

The mold of Fig. 1 is arranged for top pouring and comprises an outermold member 16 in a box or other support 17 and having a bore 18 ofsubstantially the form de sired to be'given to the exterior of thehollow casting which is to be made. The bottom mold member 19 fits intobore 18 and has an opening 20 for receiving and centering the tube 10,and-therefore the core sections 12 sleeved on tube 10, with respect tothe bore 18 of the outer mold member 16; and the mold member 21 providedwith opening 22 to fit totube 10 serves the like purpose at the upperend. Mold member 21 has an inlet opening 23 and a vent hole 24 whichconnect respectively with inlet opening 25 and vent hole 26 in thepouring piece 27, which-may likewise have an opening 28 to fit over thecentral tube 10.

For top pouring the core mold sections 12, 12 may be arranged asinverted cups slipped upon the central tube 10, with the margins 13resting respectively on the bottom of the mold and upon portion 14 ofthe solidified, as by blowing or washing it out,

next lower core mold section of the series. The joints are preferablyluted or otherwise treated to give a smooth surface to the builtup coreand thereby prevent formation of any seams or fins in the finishedcasting.

The core sections 12 shown in Fig. 1 are either hollow as shown at 12"forming an open space or recess for a part of the length of the section12 adjacent to the pipe 10,

or the recesses therein are provided with a filling of porous material12, and are adapted for giving the necessary initial support to the castmaterial and to break down upon application of shrinking or otherstresses. The hollow bodies may be poured in casting in various ways, asfor example, with the mold arranged horizontally as well as vertically.While the mold sections 12 of Fig. 1\ are best adapted for top pouring,they may be used where the position of the mold at pouring is other thanvertical, as for example with the mold arranged horizontally.

The core sections 121 of Fig. 2 are of the same form as core sections12, except that the margins 121 of each fit into a peripheral notch orcut-out 121 of the adjacent core section, thus centering each ring orsection at one of its ends upon the adjacent core ring or section. Thecentral supporting member in this case as well as in Figs. 3 to 5 isshown as a rod 10', but a tube or other form of supporting device may beused, if desired. The form of mold core section shown in Fig. 2 is welladapted for horizontal pouring as well as vertical pouring, the rod 10',which is made from metal or other material of high mechanical strength.serving to support as well as to center the core sections. When desiredand especially where the core sections are not vented through thecentral supporting member, vent openings may be provided in the coresections, as at 130, or grooves may be provided for this purposeadjacent to the supporting member as shown at 131, Fig. 2.

In Fig. 3 the core sections 122 have stepped margins 122 fitting intothe stepped peripheral notches or cutouts 122" of adjacent sections. InFig. 4 the core sections 123 have end closing portions 123 and 123 attheir opposite ends, and the core sections are not nested together orcentered at one end on one another, as in Figs. 2 and 3, but arecentered and supported at both ends on the center rodlO.

In Fig. 5 the core sections 124 are provided with grooves 124; whichserve to provide strengthening ribs on the interior of the pipe or otherhollow casting. It will be observed that such strengthening ribs are butone example of internally projecting members or portions which may beformed in the hollow casting, and that hollow castings with any desiredinterior contour or formation can be produced in accordance with thepresent invention by reason of the cores breaking down duringsolidification of the casting and being removed in the broken downcondition.

The interior of one of the mold core sections 12 is shown in Fig. 1 asbeing filled with porous material 12. such as shavings, excelsior or thelike,'or non-coml ustible porous material may be used if desired, solong as the available spaces provided are sufiicient to give thenecessary space for displaced core material when the castin shrinks.Such filling of porous material serves to give slightly added strengthto the core sections during the first stages of casting, but may bedispensed with if desired.

By my invention I have successfully molded pipes of cast steel teninches in diameter and fourteen feet in length in horizontally arrangedmolds, and hollow bodies of practically any size and dimension can beproduced from practically any metal or composition which can be meltedand poured. The cores are easil and quickly made and assembled and whilethey afford the adequate strength and support for the molten metal, arereadily collapsed when any shrinking strains appear. The cast objectsproduced are clearly and accurately molded and no difiiculty ispresented in removing the core material. lVhen desired the tube or baron which the core rings or sections are fitted can be removed while thecasting is still hot. permitting the core sand or other material to fallout of the pipe or other hollow body while still hot. thus simplifyingthe operation and permitting more rapid cooling of the hollow castingand reducing the time required for production. It is to be understoodthat the apparatus shown is for illustration only and that modificationsand changes may be made within the scope of my claims.

I claim:

1. Apparatus for casting hollow bodies. comprising a mechanically strongcore center and a plurality of collapsible mold core sections centereddirectly upon and supported by said member.

2. Apparatus for casting pipe. comprising a tube or rod. a plurality ofmold core sections sleeved on said rod and centered and supportedthere-by. said core sections having recesses therein the walls whereofare spaced away from said center member to provide spaces to receive thesand of the core sections and permit same to collapse when subjected toshrinking or the like strains.

3. Apparatus for casting pipe. which comprises a -mechanically strongcore center member and a plurality of hollow core rings sleeved thereonand making substantially a close fit therewith.

llO

Lara ear I 4. Apparatus for casting pipe, which comprises a tube or bar,a plurallty of recessed core sections centered and supported directly onsaid bar, each of said core' sections having a peripheral groove orcut-out for receiving a peripheral flange or lip upon the adjacent coresections.

5. Apparatus for making cored castings, which comprises a tube or rodfor forming the center of the core, and a plurality of core sectionssleeved thereon for a portion of their length and having internalrecesses providing hollow spaces adjacent to the tube or rod for theremainder of their length.

6. A core for making the boresof hollow castings, which comprises a tubeor rod, and a plurality of core rings of substantially cup shape, placedend to end, and

provided in their, bottoms with holes through which said tube or rod maypass, said tube or rod making substantially a close fit within saidholes.

7. A core for making the bores of hollow castings, which comprises atube or rod and a plurality of core rings of substantially cup shape,placed end to end, and provided withholes in their bottoms through whichsaid tube or rod may pass with the core rings fitting around said tubeor rod sub-u stantiall closely, and said core rings being provided withgas vents.

In testimony that I claim the foregoing, l have signed m name hereto.

ER-C A. E. ARMSTRONG.

